I don't doubt that your experience was vivid and seemed real. But you'd agree with me, I think, that your prior interest in OBE's and lucid dreaming provides a basis of suggestion out of which a quasi-hypnotic (or hypnagogic) state could develop.
I wouldn't be inclined to think that what you experienced had any basis outside of your body/brain.
Let me relate (briefly!) an experience I had. After having all four of my wisdom teeth removed at once, I was taking Darvon for pain for a couple of days. My gums became infected and my cheeks swelled up to the size of grapefruits on both sides. I felt a lot of pain. I remember lying on my living room couch and being in a state of quite excruciating pain. Then something strange happened. I felt my consciousness start to slip downwards, through my neck and into my chest! It seemed to really be happening, that my self had re-located to my chest. The state persisted for a few minutes, at least.
What happened? I was in severe pain in spite of being doped up, the source of the pain was my face (right next to my brain), and I wanted out! So I hallucinated a way out, with my conscious self sliding down below the source of the pain and so into pain-relief position.
This seemed to really happen. Clearly, it didn't. After a few minutes, I snapped into a more awake state of consciousness, and there I was, right behind my eyes, as usual. (smile)
I don't disagree with a thing you said. But at some point we all make our choices as to the best available explanation of what we experience, and we all have to admit our biases, too. Materialism is a bias, one you might argue is an eminently sensible one :-) But on the whole, I admire your inquisitive approach to factual issues, and think it is a good one.